By Lee Minji SEOUL, Aug. 25 (Yonhap) -- A U.S. jury has ruled that Samsung Electronics Co. infringed some of Apple Inc.'s mobile patents, dealing a serious blow to the leading smartphone maker in its epic battle with the iPhone maker to gain supremacy in the US$219 billion global smartphone market.

The verdict, delivered on Friday (local time), comes after a Seoul court ruled the two smartphone giants infringed each other's patents, including those for wireless technology and user interface. The Seoul ruling involved a total of 65 million won (US$57,269) of monetary compensation in addition to sales bans on the patent-infringing products.

While the ruling on Samsung's home turf was seen as a partial victory for the South Korean tech behemoth, market watchers paid more attention to the U.S. case, where the money and market clout at stake is much larger.

The non-technically inclined jury, consisting of nine Silicon Valley residents, concluded Samsung infringed six of seven patents for mobile devices and ordered the South Korean firm to pay more than US$1.05 billion in damages. Apple had sought more than $2.5 billion in compensation.

The jury determined that all of Apple's patents at stake in the trial were valid, while turning down patent infringement claims and damage payments requested by Samsung. The top smartphone maker had demanded as much as $421.8 million in royalties, arguing the Cupertino, California-based firm infringed its patents.

While the decision by the jury awaits a court ruling by district court judge Lucy Koh, market watchers assess the verdict granted an upper hand to the iPhone maker considering jury verdicts are rarely reversed in later stages.

Analysts said Samsung is likely to appeal the ruling if the U.S. judge reaffirms Samsung's patent infringements.

Following the Seoul court's decision earlier this week, Samsung said it plans to "continue to take all available measures, including legal, to counter efforts that could limit both market competition and consumer choice."